<!DOCTYPE html>
<html>
<head>
    <title>PlayCanvas Basic Button</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
    <link rel="icon" type="image/png" href="../playcanvas-favicon.png" />
    <script src="../../build/output/playcanvas.js"></script>
    <style>
        body { 
            margin: 0;
            overflow-y: hidden;
        }
    </style>
</head>

<body>
    <!-- The canvas element -->
    <canvas id="application-canvas"></canvas>

    <!-- The script -->
    <script>
        var canvas = document.getElementById("application-canvas");

        // Create the application and start the update loop
        var app = new pc.Application(canvas, {
            mouse: new pc.Mouse(document.body),
            touch: new pc.TouchDevice(document.body),
            elementInput: new pc.ElementInput(canvas)
        });
        app.start();

        // Set the canvas to fill the window and automatically change resolution to be the same as the canvas size
        app.setCanvasFillMode(pc.FILLMODE_FILL_WINDOW);
        app.setCanvasResolution(pc.RESOLUTION_AUTO);

        window.addEventListener("resize", function () {
            app.resizeCanvas(canvas.width, canvas.height);
        });

        // Create a camera
        var camera = new pc.Entity();
        camera.addComponent("camera", {
            clearColor: new pc.Color(0, 0, 0)
        });
        app.root.addChild(camera);

        // Create a 2D screen
        var screen = new pc.Entity();
        screen.addComponent("screen", {
            referenceResolution: new pc.Vec2(1280, 720),
            scaleBlend: 0.5,
            scaleMode: pc.SCALEMODE_BLEND,
            screenSpace: true
        });
        app.root.addChild(screen);

        // Create a simple button
        var button = new pc.Entity();
        button.addComponent("button", {
            imageEntity: button
        });
        button.addComponent("element", {
            anchor: [ 0.5, 0.5, 0.5, 0.5 ],
            height: 40,
            pivot: [ 0.5, 0.5 ],
            type: pc.ELEMENTTYPE_IMAGE,
            width: 175,
            useInput: true
        });
        screen.addChild(button);

        // Create a label for the button
        var label = new pc.Entity();
        label.addComponent("element", {
            anchor: [ 0.5, 0.5, 0.5, 0.5 ],
            color: new pc.Color(0, 0, 0),
            fontSize: 32,
            height: 64,
            pivot: [ 0.5, 0.5 ],
            text: "CLICK ME",
            type: pc.ELEMENTTYPE_TEXT,
            width: 128,
            wrapLines: true
        });
        button.addChild(label);

        // Change the background color every time the button is clicked
        button.button.on('click', function (e) {
            camera.camera.clearColor = new pc.Color(Math.random(), Math.random(), Math.random());
        });

        // Load a font
        var fontAsset = new pc.Asset('courier.json', "font", {url: "../assets/fonts/courier.json"});
        fontAsset.on('load', function () {
            // Apply the font to the text element
            label.element.fontAsset = fontAsset;
        });

        app.assets.add(fontAsset);
        app.assets.load(fontAsset);
    </script>
</body>
</html>
